Pivotally mounted hermetically sealed window unit

ABSTRACT

A hermetically sealed dual light window unit in which, if desired, the volume between the lights is allowed to breathe. Each window is provided with structure for allowing the window to be tilted into the building so that the outer light may be cleaned, desiccant can be replaced, etc. In an installation comprising a plurality of such window units, all are ducted to a common manifold. The manifold is ported to the atmosphere to vent air pressure built up within the system to the atmosphere, and accept filtered, dehumidified air from the atmosphere when ambient atmospheric air pressure exceeds the internal air pressure within the system.

States McCurdy et a1.

[ PIVOTALLY MOUNTED HERMETICALLY SEALED WINDOW UNIT Richard H. McCurdy; Lawrence W. Connelly, both of Fairfax, Va.

Related US. Application Data Continuation-impart of Ser. No. 101,258, Dec. 24, 1970, abandoned.

[75] Inventors:

11] 3,81,331 51 May 14,1974

Primary Examiner-Kenneth Downey Attorney, Agent, or Firm-Smyth, Roston & Pavitt [57] ABSTRACT A hermetically sealed dual light window unit in which, if desired, the volume between the lights is allowed to breathe. Each window is provided with structure for allowing the window to be tilted into the building so that the outer light m'ay be cleaned, desiccant can be 52 us. Cl 49/401, 49/484, 52/172 replaced, In an installation comprising a plurality [51] Int. Cl E05d 7/00 of such Window units are ducted to a Common 58 Field of Search 49/383, 399, 400, 401, manifold The manifold is Ported to the atmosphere to 49 5 7 7 3 3 vent air pressure built up within the system to the atmosphere, and accept filtered, dehumidified air from 5 References Cited the atmosphere when ambient atmospheric air pres- UNITED STATES PATENTS sure exceeds the internal air pressure, within the syst 3,604,163 9/1971 Mc Curdy et a1 52/172 em 3,220,062 11/1965 Hermann 49/484 15 Claims, 8 Drawing Figures If a "Q 4 1 0 a b a a I,

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PATENTEDMAY 14 1974 SHE! 3 (IF 3 occupants.

PIVOTALLY MOUNTED HE ETllCALLY SEALED WWDOW UNIT This is a continuation-in-part of US. Pat. application Ser. No. 101,258 filed Dec. 24, 1970 by Richard H.

McCurdy and Lawrence W. Connelly, and now abandoned, the disclosure of which is hereby incorporated herein.

BACKGROUND OF THE INVENTlON Construction of major office buildings has accelerated rapidly in the last few years and advances in the tions of building use so that a proper balancing of the systems may be maintained at all times. In order to ensure that the windows stay closed, such construction usually utilizes windows which cannot be opened, short of breaking the glass or removing the entire window.

Since the large number of the newer major office buildings and apartment houses are being built in the midst of highly urbanized areas, it is desirable and necessary that, as far as possible, the buildings be soundproofed so that external street, construction, etc., noises do not penetrate the buildings and disturb the Ideally, such a building would be manufactured without any windows so that the structural, airtight, and sound integrity of the building could be maintained at all times. On the-other hand, people prefer to work and live in buildings having windows so that they are able to look out at their surroundings and use sunlight to illuminate the building interiors.

In order to achieve the abovedescribed desired results, architects and builders have found it expedient'to employ windows having a plurality of lights, i.e., panes of glass, so that the air space between the lights serves as both a sound attenuation device and'a heat barrier.

Over the past few years, such windows have been rapidly improved in avariety of ways, some of which have been illustrated in US. Pat. application Ser. No. 81,857 filed Oct. l9, 1970 now U. S. Pat. No. 3,685,239, the teachings of which are hereby incorporated herein.

While these window improvements have proven to be significant, the, only wayv that the outside of the windows can be washed is by the installation of rigging on the outside of the building which may be raised and lowered so that window washers can reach the outside of the exterior light of each window in the building. Similarly, if a window should be broken, it is standard procedure to remove the entire window from the wall of the building and replace it, rather than attempting to replace the light with the window in place. Each of these tasks is both difficult and time-consuming and di minish the overall advantages of having such windows.

Additionally, these window units also pose two major problems moisture control and pressure compensation. lf the air trapped within the sealed air space between the glass panels contains even a small quantity'of water vapor, changes in air temperature and pressure within the air space and changes in the temperature of the lights themselves may cause condensation to form on the inner faces of the lights and frame. Repeated or extended exposure to moisture leads to the deposit of unsightly film or scum on the glass surfaces; such moisture also tends to attack the frame material and may lead to the deterioration and eventual destruction of the vital glazing gasketsand sealant.

At the same time, changes in the air pressure within the sealed air space and inside and outside of the building in which the unit is installed exert varying forces on the glass panes. With relatively small panes the effect of the variations is hardly noticeable, but with large units the resilient glass may be visibly distorted. In some cases the bending or bowing is so pronounced as to spoil the aesthetic appearance of the installation. Under extremely adverse conditions the glass can even be broken by the stresses generated, unless it is shatterproof.

Since many new buildings are being built in which a large percentage of the outer walls are glass and since all glass will produce at least some reflection, the aesthetic appearance of a building, as seen from a distance, will be vastly enhanced if a person viewing it sees a non-distorted image on the windows. ln buildings in which the outer light of each multi-light windows undergoes some or all of the distortion which occurs due to pressure variations, a person looking at the building sees very unpleasant reflections which create the illusion that the building is somehow improperly constructed or located.

Distortion in window glass is created by variations in pressure on the opposite sides of the glass. Of course, the pressure on the outside of a window in a building wall is created and controlled only by atmospheric conditions. On the other hand, the pressure on the interior of the window is controlled by those same atmospheric conditions, to some extent, as well as by air conditioning units, elevators moving up and down within the building, etc. Thus it becomes apparent, that if the outer light or pane of a multi-light window is to remain distortion-free, it is necessary that the pressure between the lights and the pressure on the exterior of the wall in which the window is mounted remain substantially equal. This will allow any distortion which must be absorbed by the window to be absorbed by the inner pane. A person'viewing the building from a distance cannot see any distortion on the inner pane and a person standing inside the building will not have his view of the outside distorted by the distortion of the inner pane since he will normally be standing close enough to it to prevent his eyes from observing the distortion. Thus, some means for accomplishing this result must be produced.

Commonly, steps are taken in the manufacture of such units to avoid the introduction of moisture into the air space before it is sealed. Any moisture inadvertently trapped within the sealed unit is removed by providing a desiccant material in the air space. This desiccant serves, in addition, to absorb the miniscule amount of moisture that invariably manages to migrate into the air space from various sources. If sufficient desiccant is used, as long as the unit remains hermetically sealed protection is afforded for many years against condensation and moisture-induced scum formation or deterioration. Eventually, however, even in the most effectively sealed units the desiccant becomes saturated and free moisture begins to accumulate.

Compounding this problem, changes in the pressure differential within and without the units cause even the smallest air leak to allow the passage of air between the atmosphere and the inside of the sealed unit. This process greatly reduces the time needed for a sufficient quantity of moisture to be drawn into the enclosed air space to saturate the desiccant and cause condensation, scumming, and corrosion.

Whatever the cause, when this occurs, the entire unit is generally replaced because of the difficulty and expense of recharging the exhausted desiccant and resealing the glass or frame. In those few prior art windows designed to provide means for recharging the exhausted desiccant without removing a glass pane, even if the air leak can be sealed conveniently, replacing the desiccant is at least a laborious and time-consuming undertaking.

SUMMARY OF THE INVENTION The present invention relates to such a multiple light window which has all of the desired features of the presently available windows and which may be easily and quickly opened or removed by authorized workmen to eliminate the disadvantages described above.

The invention further relates to such windows and their connection and use with a common manifold system to which a plurality of the windows are ducted.

More specifically, the invention relates to such a window in which a pair of lights may be mounted within a subframe. The sub-frame may, in turn, pivot on a main frame which may be mounted in the wall of the building. Relative movement between the frames allows the exterior light to be worked on without requiring elevator rigs or scaflolding. The sub-frame may be hinged to the main frame at a suitable interface and, when the window is closed, may cooperate with a system of seals which prevent the leakage of air, heat, or noise between the main and the sub-frames.

A series of seals may be provided at suitable positions, such as at each of the inner and outer edges of the window, in order to be doubly effective. In other words, the series of seals which may be provided for the outer portion of the window prevent air, dirt, moisture, etc., from traveling between the exterior of the building and that part of the main frame-surrounding the window when it is in place. The inner set of seals may be installed to prevent such communication between the interior of the building and the area of the main frame about the window. Thus, air, noise, etc., cannot pass in either direction through the window frame.

If desired, the lights may each be mounted in continuous gaskets within a sub-frame which can be suitably constructed to allow the application of a continuous bead of sealant which substantially encloses the volume between the lights in the manner taught in our abovecited US. Pat. No. 3,685,239.

Consequently, with the structure thus far described, an essentially sealed window unit may be mounted in such a way as to allow the window to be quickly and easily opened so that the exteriors of both lights may be washed from inside the building or the external light can be repaired or replaced. Additionally, if the environmental control systems within the building should fail, the windows may be opened for ventilation. On the other hand, when the windows are closed, dirt, moisture, and noise cannot penetrate from outside to the building interior.

If desired, the problems previously described relative to penetration of dirt andmoisture into the volume between the lights and the distortion of the outer light due to pressure differentials can also be obviated by the instant invention. The windows may each be connected to a common manifold or breather system of the type described in our US. Pat. No. 3,604,163 issued Sept. 14, 1971 which teachings are hereby incorporated herein.

The otherwise hermetically sealed air spaces within all windows or certain groups of windows in a building or group of buildings may be ducted to a common manifold so that pressure variations within the air spaces are transmitted to the manifold. The manifold in turn is ported to the ambient atmosphere, preferably outside of the building in which the window units are installed, through an air dehumidifying and filtering device. On the other hand, in many installations, it will be suitable to vent the manifold to a space within the same or another building which is located and designed so that it normally has substantially the same pressure as that on the exterior of the building in which the window units are mounted.

When the pressure within the manifold is greater than the ambient outside pressure, this device permits air to escape to the atmosphere. When ambient outside pressure exceeds the manifold pressure, it permits air to enter the manifold for distribution to the individual window units. The air within the window units and the manifold is continuously exposed to a desiccating material contained in the dehumidifying device. Any moisture in this air migrates under the influence of its partial pressure to the desiccant, where it is absorbed. This desiccating material is positioned in the stream of all fresh atmospheric air drawn into the manifold, and effectively removes any moisture which might otherwise find its way to the individual window units. The dehumidifying and filtering device may be constructed with alternate air-flow paths passing through two or more desiccant towers. Means may be provided for drying the exhausted desiccant in one of these towers while the others are in use.

The volume between the lights may be in communication with a central air-cleaning and drying system such as that disclosed in the above cited US. Pat. No. 3,604,163. This might,'for example, be accomplished by providing a flexible hose which would fit between the sub-frame and the main frame so that the sub-frame can be pivoted in and out of the main frame without interrupting the communication of the volume and the central air system.

This feature of the invention is considered to be significant since it allows such windows to be washed, repaired, etc., without necessitating disruption of the pressure compensating or breather system. Thus, the invention combines the advantages of having a totally hermetically sealed window, an openable window, and a system for compensating for the pressure differences between different window volumes and the outside of the building. In other words, use of all of the features of the invention provides an openable, dirt, moisture, and noise shielding window which, when closed, presents an aesthetically appealing,distortion-free reflection to a person standing outside the building because the outer light is not distorted by pressure differences.

Further, the invention provides for the use of an easily treated and/or replaced desiccant material for all windows connected to the breather system rather than a distinct desiccant reservoir for each window.

Other advantages, objects, modes, and embodiments of the present invention will become known to those skilled in the art as they read the following Detailed Description with reference to the accompanying drawings. It is realized that the description and drawings merely illustrate what is presently considered to be the preferred embodiment of the best mode contemplated for utilizing the novel principles set forth in the claims and that the claims, rather than the description, define the scope of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a'partial vertical sectional view of a window formed in accordance with the present invention;

FIG. 2 is an isometric view of a portion of the window shown in FIG. 1, illustrating the formation of the sets of seals against which the inner and outer portions of the sub-frame abut when the window is closed;

'FIG. 3 is a partial sectional view of a portion of the main frame, illustrating the structure by which the seal sets are held inthe main frame; and

FIG. 4 is a partial isometric illustration of an alternate embodiment of the hinge structure by which the subframe may be attached to the main frame;

FIG. 5 is a fragmentary elevational view of the face of a building containing a typical installation of hermetically sealed window units employing the subject invention;

FIG. 6 is a top plan view of a complex of buildings, some attached and some detached, employing the subject invention;

FIG. 7 is a perspective view of two typical hermetically sealed window units, showing the individual and common ducts utilized in one embodiment of themvention to connect their sealed air spaces with the common manifold; and

FIG. 8 is a diagrammatic view illustrating one construction of the dehumidifying and filtering unit of the subject inventionand its relationship with the window unit installation of 5'.

I DETAILED DESCRIPTION Referring now to FIG. 1, thereis shown a building wall 11, in which a sealed double glazed window unit 12 may have a main frame 13 mounted by suitable means such as bolts 15. A sub-frame 17 may be mounted in the main frame at a hinge 18 by means of which the sub-frame may be moved between the position shown in FIG. 1 and a position substantially at right angles thereto, toward the right as viewed in the drawing. Of course, the hinge 18 could be located along any of the other three edges of the sub-frame, if desired, allowing the window to pivot about either a vertical or horizontal axis. Such a variation would require a simple alteration of the frame mating structure which will be within the skill of the art once this Description has been read.

In general, sub-frame 17 may comprise a multisection wall 19 which extends about the periphery thereof and has a continuous outer flange or glazing fin 21. A continuous inner flange or glazing fin 23 also may extend inwardly from the wall 19. A continuous gasket 25 or similar device of any suitable material may be mounted on each of the fins 21 and 23 and a light or window-pane 27 may be sealingly located relative to each of the gaskets.

A continuous bead of sealant 29 may be positioned about the periphery of each of the lights 27, if desired, to ensure proper sealing between the lights and the gaskets. Another continuous sealant bead 31 may also be positioned between each of the gaskets 25 and the inner surface of the wall 19 to prevent leakage between the gasket and the wall. Although the beads 25 and 27 are both illustrated as being on the outside of the volume contained between the lights, either of them may, if desired, be formed on the other side of its respective gasket so as to be within the volume.

As described in our above cited US. Pat. No. 3,685,239, at the junctions of the various sections of the wall 19, small apertures may be drilled in the fins so that transverse beads may be used across the junctions of the wall sections to join the opposite sealant beads 31 and prohibit air or moisture from outside or inside the building from entering the volume between the lights 27.

' A pan 37, which may, for example, have suitable legs 39 which can be held by slots in the fins 21 and 23, may

be used to retain an acoustical filing material 41, such as polyurethane foam or the like, against the inner surface of each wall section 19 to provide an additional sound-deadening effect in the volume between the lights. If desired, the surface of the pin 37 can be perforated in any suitable manner to allow sound absorption by the acoustical material as well as a pleasing aesthetic effect when it is viewed through either of the lights 27.

Although a desiccant of any well-known type may be positioned between the wall 19 and the acoustical material 41 as taught in the above cited US. Pat. application Ser. No. 81,857, if desired, it is envisioned here that a flexible hose 45 may be used to connect a manifold 47 to the volume contained between the lights 27. In this manner, a plurality of such windows may be commonly connected to a suitable air filtration and drying unit, as will be described later.

As shown in FIGS. 2 and 3, at the outer side of the main frame 13 a pair of vertical flanges 51 maybe formed integral with. the main frame and extend inwardly therefrom. Each of the flanges 51 may be provided with any suitable structure such as a T-slot 53 into which a similarly shaped portion of a seal member 55 may be inserted for retention of the seal against the flange.

A similarly shaped flange member 57 may be formed integral with the main frame 13 and extend inwardly therefrom along its upper edge (FIG. 1). Similarly, the

' flange 57 may also be provided with suitable structure such as a T-slot 59 into which a suitably shaped seal member 61 may be inserted. At the lower, outer edge of the main frame 13, a flange member 63, having an offset portion 65, may also be provided with a T-slot 67 or similar device in the offset portion for retention of a seal member 69 therein. When the window unit is assembled, the seal members 55, 61, and 69 assume substantially the relationships illustrated in FIG. 2. In other words, they are so related as to form a complete seal about a defined periphery, although their precise abutment relationships may be altered if desired.

It can be seen by comparing FIGS. 1 and. 2 that the sealing members 55 and 61 are mounted so that they provide sealing faces which are substantially perpendicular to the arc of relative movement between the frames, whereas seal member 69 presents a face which is substantially parallel thereto. This relationship allows complete sealing between the window frames without producing damaging scuffing on the seal 69 which is closest to the pivot hinge.

When they are manufactured, the four seal members may be formed in a somewhat oval shape. Then, when the sub-frame 17 is closedagainst the seal members, as shown in FIG. 1, they become flattened and enter into close contact with one another to prevent the passage of air, etc., between the sections and between the frames.

At the inside of the window, similar vertical flanges 73 (FIG. 2) may be suitably formed to retain seal sections 75, and an upper horizontal flange 77 (FIG. 1) may be formed to retain a seal member 79 therein. The flanges 73 and 77 and the seal members 75 and 79 may be quite similar. to the flanges 51 and 57 and the seal members 55 and 61, respectively.

At the lower inside edge of the window, however, a flange member 83, having an angularly offset section 85, may be formed with a T-slot 87 for retention of a seal member 89 therein.

Thus, when the window is closed, as shown in FIG. 1, the seal members 75, 79, and 89 are flattened against one another as pressure is exerted thereag'ainst by contact with the flange 91 as the window is closed. This prevents the passage of air therebetween, as shown in FIGS. 1 and 2.

In other words, the seals are so mounted and interrelated, regardless of the structure actually used, that they can present a positive barrier to air, dirt, moisture, noise, etc., on either side of the window.

A flange 91 of the sub-frame 17 which extends about the periphery of the inner edge thereof may be provided with a suitably related surface thereon, such as is shown at 93 which cooperates with the seal member 89 to flatten it so that the four seal sections effectively prevent the passage of air, etc., from inside the building to the volume between the main and sub-frames but allow the window to be opened and closed without causing a scuffing of the seal 89, Le, that closest to the pivot hinge, which could eventually destroy its effectiveness.

It is thus seen that the seals in each set, which are closest to the pivot hinge, regardless of which of the four sides or edges of the window the hinge is installed on, may be angularly related to the arc of window pivot at predetermined angles, so as to be substantially parallel to the pivot arc and to produce effective sealing along those edges of the frames without causing wear and tear on the seals when the window is opened and closed.

If desired, inner window trim members 95 and/or outer window trim members 97 may be fastened to the sub and main frames respectively to provide the windows with a more attractive appearance. The trim members may be fastened to the frames in any suitable fashion, such as that illustrated in the drawings.

While it is envisioned that any suitable hinge, such as piano hinge 18, may be used to pivotally mount the sub-frame 17 on the main frame 13 by attaching the hinge to flange 91, an alternate embodiment of such a hinging apparatus has been illustrated in FIG. 4 wherein those elements which are substantially identical to those of the preferred embodiment have been illustrated with similar identification numerals, each prcceded by the numeral 1," whereby main frame 13 becomes main frame 113, etc. Further description of these elements is therefore deemed unnecessary.

An extension 201 is formed on the hinge section 191 of a suitable window and is provided with an integral, cylindrically shaped male hinge pin 203 which may be captured between a semicircular groove 205 and a plurality of female hinge brackets 207 suitably attached to the main frame 113. In order to provide for the relative movement between the frames, a plurality of slots 209 are formed in the extension 201 to allow the hinge member 207 to pass therethrough and firmly grip the male hinge member 203 against the groove 205. Of course, this structure could also be utilized for a vertical axis hinge, if desired.

Although not shown in the drawings, any suitable device which will hold the frames in the relative positions of FIG. 1 may be used to hold the window closed until it is necessary for maintenance personnel to open it.

Referring now to FIG. 5, the building 11 has been illustrated as comprising a plurality of stories, each having a number of sealed double glazed window units 12 of the type described. It should be realized, of course, that the present invention does not restrict they use of such windows to a multi-story building. Rather, the invention can also be used in single story, split level, semi-detached, multiple, or other type building applications. For example, as shown in FIG. 6, the windows may be employed in a building complex comprising a number of wings or detached building units Ila-11f.

In any event, each window unit 12 is attached to the common manifold system 47 by suitable means such as a flexible hose 45 as described with reference to FIG. 1. Of course, any suitable tubing or piping may be used to attach each of the windows to the manifold, so long as it does not prevent or restrict the ability of the window to be opened. Similarly, the manifold system 47 can be constructed from any suitable piping or tubing, such as commercially available polyethylene, so long as the tubing 45 and the manifold 47 are properly sealed to prevent leakage.

In some cases, it may be desirable to employ separate manifold-ducts 47 for different windows or series of windows but, in most cases, a single manifold system in the wall adjacent the windows will suffice. In the example shown in FIG. 5, for example, a plurality of horizontal manifolds 47 are connected to one another by means of a vertical manifold 211.

In FIG. 6, the building complex is shown to illustrate how it might be formed so that a vertical manifold will connect the horizontal manifolds on the various floors of the building and the vertical manifolds can be interconnected by any suitable means such as piping 213. In other words, the manifolds, both vertical and horizontal, can be located in any convenient position within or between the buildings, whether above ground or underground, so long as they properly serve to connect the tubing 45 of each window to a conveniently located de humidifying and filtering unit 215. It should be apparent that in some installations it may be desirable to provide a plurality of dehumidifying and filtering units but, in many instances, it will be preferable to utilize only a single unit.

The unit 215 may be of any suitable and readily available dehumidifying and filtering device comprising a pair of desiccant towers 217 and 219 containing any commonly available desiccant 221. Such units also may comprise, for example, a pair of four-way inlet and outlet valves 223 and 225, respectively, a particle filter 227, and a timer 229.

The arrows in FIG. 8 indicate the direction of airflow through the unit 215 when the ambient atmo- 'spheric pressure is greater than the air pressure within the common manifold 47. If the atmospheric pressure is less than that within the air spaces 19, the airflow would be in the opposite direction.

When the ambient air pressure is greater than that within the common manifold, which may be the result of an increase in ambient barometric pressure or a low ering of the temperature of the air in the air spaces 19 of the window units 12, or both, atmospheric air will enter the system through a port 231 and pass through a dust filter 233 which removes large solid impurities from the air. Valves 223 and 225, having been actuated by the timer 229 to the positions illustrated, for example, will direct the incoming air through the desiccant tower 217, a dewpoint indicator 237, and the filter 227 into the common manifold 47., As the air passes through the tower 217, it will be purged of moisture by the desiccant 221 so that no moisture will be introduced into the manifold 47 or the various window units 12.

A purge blower 239, which may also be actuated by the timer 229 may, in the meantime, be directing a stream of air, which may be preheated, through the desiccant tower 219 to remove any moisture which may have been accumulated in the desiccant therein during prior use. The moisture-laden air coming from the tower 219 then passes through the valve 223 and out through a discharge port 241.

If indicator 237 senses that moisture is present in the system, the unit 215 may, if properly programmed, change the valves 223 and 225 to automatically place the desiccant tower 219 into use, shutting off the flow of incoming air through the tower 217. it will be understood that the timer 229 may be preset to automatically reverse the valves 223 and 225 before the desiccant 221 in the tower inuse has been exhausted so that the air present in the manifold system is always moisture:

free. Additionally, the moisture detection unit 237 may particles which may remain in the air, after it has passed through the unit 215 and also to maintain the cleanliness of the air spaces 19 within the window unit 14. Of

course, it will be realized by those skilled in the art that any other suitable system desired may be utilized in place of that illustrated at 215, so long as the manifold 47 is allowed to breathe through atiltering and drying system to the ambient atmosphere.

According to the theory of partial pressures, each of the various elements, etc., which combine to form what is commonly referred to as air, tend to be equally distributed throughout any given volume. It has been shown that this theory is particularly applicable to moisture in the air. Consequently, assuming for a moment that there is no flow of air through the dehumidifying and filtering unit 215 in either direction, as the moisture in the manifold adjacent the desiccant is absorbed, that moisture which is present in the manifold further away-from the desiccant, and that within the window units 12 themselves, will tend to migrate toward the desiccant to maintain an equal distribution of moisture in the air throughout the breather system. Thus, even if air did not pass through the unit 215, the migration of the moisture in accordance with the principleof partial pressures would achieve substantially the same dehydrating result, causing air within the system to become more and more dry as time goes by, so long as the desiccant is properly conditioned to accept moisture. Therefore, the selection and use of any suitable system of this type will cause all of the moisture which naturally migrates through glass, metal, rubber, etc., over a long period of time, to be removed from the air due to the action of partial pressures.

lt will be understood by those skilled in the art that if the temperature within the air spaces 19 increases, or if ambient atmospheric barometric pressure should decrease, or both, so that the pressure within the breather system becomes greater than that of the ambient atmosphere, the flow'of air through the system will be such that air is exhausted from the port 231 rather than drawn into the port.

Thus it will be realized, that if one of the glass panes 27 should be broken in any window, the remainder of the installation would remain in a substantially moisture-free condition since the amount of moisture entering the total system through any exposed tubing 45 over a short period of time would be relatively small. When the broken pane is replaced, the system will automatically begin to dehumidify the air throughout its entirety. Y

In other words, air within the system will be constantly undergoing a dehumidification process either as a result of the migration under the principle of partial pressures or as a result of movement of the air into and out of the system asa result in changes in pressure differentials.

Of great importance, however, is the fact that the port 231 is exposed to a volume which has substantially the identical pressure as that on the outside of the windows. In other words, if the windows are mounted in an outside wall of the building, the port 231 may be vented either to the outside of the building or to a space inside the building which has a-pressure equal to that outside of the building at all times.

Alternatively, if the windows are mounted on the inside of the building, such as on an enclosed mall, the port 231 would be vented to a volume having the same pressure as that within the mall and on the outer side of the windows. The port 231. thus is exposed to the outside of the window or to a volume which has a pressure substantially identical to that on the outside of the window, i.e., on the left side of the window 12 depicted in FIG. 1. Construction of thesystem in this manner will cause the volume or air space 19 to be at substantially the same pressure as that outside the window, i.e., on the left of the left-hand light 27. Thus, in some instances, there may be a pressure differential between the pressure in the air space 19 and that to the right of the inside light 27, i.e., that on the right-hand side of P16. 1, but there will be no pressure differential between the opposite sides of the left-hand light.

As a result, if any distortion occurs within the window, it will be on the inside light and that distortion will be substantially indiscernible to a person standing inside the building and invisible to a person standing outside the building.

On the other hand, the outer light will not be distorted and a reflection in the building windows will be true and clear. This feature will make a substantial difference in the appearance of a building from the outside since the building itself and the image it reflects will be distortion-free and very attractive to a person looking at the building. On the other hand, when it becomes necessary to open one or more of the windows for washing, repairs, etc., the breather system will not be additionally exposed to the air and the pollutants and moisture therein. Therefore, the interiors of the windows will remain clean and free of scum, reducing maintenance costs and increasing the enjoyment of the building occupants.

Thus the present invention provides embodiments of an openable window which is distortion-free, as viewed from the outside, and remains clean in the air space between the windows. It will now be realized by those skilled in the art that the applicants have thus made a significant advance which extends 'well beyond that set forth in this description or illustrated in the drawings. Consequently, many further modifications, alterations, embodiments, etc., of these concepts may be devised by those skilled in the art without exceeding the scope of the invention as defined in the following claims, wherefore What is claimed is:

1. A window comprising a main frame mountable within a building wall, defining a window opening therein, and including first means defining a seal about said window opening adjacent the outer edge thereof and comprising a plurality of expandable members oriented in different planes,

second means defining a seal about said window opening adjacent the inner edge thereof and comprising a plurality of expandable members oriented in different planes,

a sub-frame pivotally mounted on said main frame for movement into said window opening and comprising first and second sealing surfaces, each having portions thereof oriented in distinct planes for cooperation with said first and second seal means,

a peripheral member having spaced, inwardly directed glazing fins formed on the inner face thereof and a resilient structural gasket mounted on each of said fins adapted to receive and maintain airtight contact with the edges of glass panels, and

glass panels mounted in each gasket and defining, with said gaskets, fins, and peripheral member, a hermetically sealed airspace, and flexible communication means for connecting said otherwise hermetically sealed airspace to an air filtration and drying system, regardless of the relative pivotal positions of said main and sub-frames. 2. The apparatus of claim 1 including a manifold in the building in which the window is mounted and connected to said flexible means, a plurality of such windows, each similarly in communication with said manifold. 3. The apparatus of claim 2 including means connected to said manifold for cleaning and drying air therein.

4. The apparatus of claim 2 including means in said manifold forming an open port at a location at which the ambient pressure is substantially identical to that pressure on the outside of the building wall.

5. A plurality of window units for installation in the wall of a building defining a substantially enclosed volume, each unit comprising a main frame having sealing means formed therein, a sub-frame having a sealed volume contained therein between a pair of laterally spaced window panes, means for pivotally mounting said sub-frame in said main frame for movement of said sub-frame against said sealing means to prevent the passage of air and moisture between said frames, and

means, distant from said main frame, for removing moisture from within the said sealed volumes of each of the plurality of window units and for maintaining each said window unit substantially free from visual distortion as viewed from the exterior of said enclosed volume, said means comprising:

a hygroscopic material,

first flexible air passage means providing communication between each said otherwise sealed volume and said hygroscopic material regardless of the relative pivotal positions of any of said main and sub-frames, and

second air passage means providing continuous communication between said hygroscopic material and a relatively unconfined volume, as compared to said sealed volume, in which the atmospheric pressure substantially corresponds to the atmospheric pressure prevailing exteriorally of said enclosed volume.

6. An openable window having parallel panes therein separated by an air space comprising a main frame mounted in the wall of a building defining a main frame opening and having an inner edge at the inside of the building wall and an outer edge at the outside of the building wall, seal means mounted in said main frame adjacent each of said inner and outer edges and extending entirely about the periphery of saidmain frame opening, at least one portion of each of said inner and outer edge seal means being so positioned as to be angularly related to the common plane of the remainder of each said seal means, a sub-frame pivotally attached to said main frame along one edge thereof and having inner and outer edge sealing surfaces operatively aligned with said inner and outer edge sealing means, at least one portion of said inner and outer edge sealing surfaces being angularly related to the common plane of the remainder of said inner and outer edge sealing surfaces whereby said sub-frame may be pivoted into and out of said main frame opening without causing said sub-frame sealing surfaces to scuff or wear said seal means, at least two glazing fins extending inwardly from said sub-frame,

glazing gaskets mounted on each of said fins, each sealingly supporting one of said parallel panes, and a means for sealing each said glazing gaskets to said sub-frame about the entire periphery thereof. 7. The window of claim 6 including means for filtering and drying the air in said air space.

8. The window of claim 6 including means located at a position remote from said window for allowing said air space to breathe through an air filtration and drying means to a relatively unconfined volume having a pressure substantially equal to that at said outer edge of said main frame, and

means connecting said air space to said breathing means in sealing relationship thereto whereby said air space may receive or exhaust air only through the air filtration and drying means, regardless of the pivotal relationship of said main frame and said sub-frame.

9. In a building having .a plurality of windows, each comprising a main frame supporting a sub-frame therein in hermetically sealed relationship thereto at the respective inner and outer edges thereof, each said sub-frame supporting at least two parallel window panes therein in hermetically sealed relationship so as to define an airspace therebetween, means for allowing said otherwise hermetically sealed air spaces to breathe through a common manifold, air drying material, and filter to a relatively unconfined volume having substan tially the same pressure as that on the outside of the building, means for pivoting each 'said sub-frame relative to one edge of said-main frame to temporarilydisrupt the hermetic seal between said main and subframes of said windows, and means for maintaining the otherwise hermetically sealed relationship of every said' air space and the connection thereof to said breathing means, regardless of the pivotal relationship of said frames.

10. A window unit comprising a main frame mountable in a building wall and definparallel to the plane defined by said main and subframes when they are pivotally aligned,

second seal means in said opening and supported by said main frame in a second plane which is angularly related to said first plane, said first and second 7 seal means being closely adjacent near the ends thereof to define a continuous seal about said opening,

third seal means on at least one edge of said subframe and oriented in said first plane, and

fourth seal means on at least one peripheral wall of said sub-frame and oriented in said second plane, said third and fourth seal means being closely adjacent near the ends thereof to define a continuous seal about the exterior of said sub-frame such that said first and third and said second and fourth seal means cooperate to positively seal said main and sub-frames when they are pivotally aligned.

11. The window of claim 10 in which said second plane is perpendicular to said first plane and said second and fourth seal means extend along the same side of said window as the means by which said frames arepivotally connected, separated therefrom by the depth of said sub-frame.

12. The window of claim 10 in which said second plane is at an acute angle relative to said first plane and said second and fourth seal means extend along the same side of the window as the means by which said frames are pivotally connected and are closely adjacent the pivotal connection thereof.

13. The window of claim 10 including 1 a plurality of windowpanes mounted in said sub frame in sealed relationship therewith and spaced from one another to define a sound attenuating airspace therebetween.

14. The window of claim 13 including means for connecting said airspace to an air drying and filtering breather system regardless of the relative pivotal positions of said main and sub-frames.

15. The window of claim 10 wherein said first through fourth seals are substantially duplicated near the inner and outer edges of the window to define a sound attenuating airspace between said main and sub-frames when said frames are pivotally aligned and saidwindow is fully closed. 

1. A window comprising a main frame mountable within a building wall, defining a window opening therein, and including first means defining a seal about said window opening adjacent the outer edge thereof and comprising a plurality of expandable members oriented in different planes, second means defining a seal about said window opening adjacent the inner edge thereof and comprising a plurality of expandable members oriented in different planes, a sub-frame pivotally mounted on said main frame for movement into said window opening and comprising first and second sealing surfaces, each having portions thereof oriented in distinct planes for cooperation with said first and second seal means, a peripheral member having spaced, inwardly directed glazing fins formed on the inner face thereof and a resilient structural gasket mounted on each of said fins adapted to receive and maintain airtight contact with the edges of glass panels, and glass panels mounted in each gasket and defining, with said gaskets, fins, and peripheral member, a hermetically sealed airspace, and flexible communication means for connecting said otherwise hermetically sealed airspace to an air filtration and drying system, regardless of the relative pivotal positions of said main and sub-frames.
 2. The apparatus of claim 1 including a manifold in the building in which the window is mounted and connected to said flexible means, a plurality of such windows, each similarly in communication with said manifold.
 3. The apparatus of claim 2 including means connected to said manifold for cleaning and drying air therein.
 4. The apparatus of claim 2 including means in said manifold forming an open port at a location at which the ambient pressure is substantially identical to that pressure on the outside of the building wall.
 5. A plurality of window units for installation in the wall of a building defining a substantially enclosed volume, each unit comprising a main frame having sealing means formed therein, a sub-frame having a sealed volume contained therein between a pair of laterally spaced window panes, means for pivotally mounting said sub-frame in said main frame for movement of said sub-frame against said sealing means to prevent the passage of air and moisture between said frames, and means, distant from said main frame, for removing moisture from within the said sealed volumes of each of the plurality of window units and for maintaining each said window unit substantially free from visual distortion as viewed from the exterior of said enclosed volume, said means comprising: a hygroscopic material, first flexible air passage means providing communication between each said otherwise sealed volume and said hygroscopic material regardless of the relative pivotal positions of any of said main and sub-frames, and second air passage means providing continuous communication between said hygroscopic material and a relatively unconfined volume, as compared to said sealed volume, in which the atmospheric pressure substantially corresponds to the atmospheric pressure prevailing exterIorally of said enclosed volume.
 6. An openable window having parallel panes therein separated by an air space comprising a main frame mounted in the wall of a building defining a main frame opening and having an inner edge at the inside of the building wall and an outer edge at the outside of the building wall, seal means mounted in said main frame adjacent each of said inner and outer edges and extending entirely about the periphery of said main frame opening, at least one portion of each of said inner and outer edge seal means being so positioned as to be angularly related to the common plane of the remainder of each said seal means, a sub-frame pivotally attached to said main frame along one edge thereof and having inner and outer edge sealing surfaces operatively aligned with said inner and outer edge sealing means, at least one portion of said inner and outer edge sealing surfaces being angularly related to the common plane of the remainder of said inner and outer edge sealing surfaces whereby said sub-frame may be pivoted into and out of said main frame opening without causing said sub-frame sealing surfaces to scuff or wear said seal means, at least two glazing fins extending inwardly from said sub-frame, glazing gaskets mounted on each of said fins, each sealingly supporting one of said parallel panes, and means for sealing each said glazing gaskets to said sub-frame about the entire periphery thereof.
 7. The window of claim 6 including means for filtering and drying the air in said air space.
 8. The window of claim 6 including means located at a position remote from said window for allowing said air space to breathe through an air filtration and drying means to a relatively unconfined volume having a pressure substantially equal to that at said outer edge of said main frame, and means connecting said air space to said breathing means in sealing relationship thereto whereby said air space may receive or exhaust air only through the air filtration and drying means, regardless of the pivotal relationship of said main frame and said sub-frame.
 9. In a building having a plurality of windows, each comprising a main frame supporting a sub-frame therein in hermetically sealed relationship thereto at the respective inner and outer edges thereof, each said sub-frame supporting at least two parallel window panes therein in hermetically sealed relationship so as to define an airspace therebetween, means for allowing said otherwise hermetically sealed air spaces to breathe through a common manifold, air drying material, and filter to a relatively unconfined volume having substantially the same pressure as that on the outside of the building, means for pivoting each said sub-frame relative to one edge of said main frame to temporarily disrupt the hermetic seal between said main and sub-frames of said windows, and means for maintaining the otherwise hermetically sealed relationship of every said air space and the connection thereof to said breathing means, regardless of the pivotal relationship of said frames.
 10. A window unit comprising a main frame mountable in a building wall and defining an opening, a sub-frame pivotally attached to said main frame along one edge of each said frame for movement into and out of said opening, first seal means in said opening and supported by said main frame in a first plane which is substantially parallel to the plane defined by said main and sub-frames when they are pivotally aligned, second seal means in said opening and supported by said main frame in a second plane which is angularly related to said first plane, said first and second seal means being closely adjacent near the ends thereof to define a continuous seal about said opening, third seal means on at least one edge of said sub-frame and oriented in said first plane, and fourth seal means on at least one peripheral wall of said sub-frame and oriented in said second plane, saiD third and fourth seal means being closely adjacent near the ends thereof to define a continuous seal about the exterior of said sub-frame such that said first and third and said second and fourth seal means cooperate to positively seal said main and sub-frames when they are pivotally aligned.
 11. The window of claim 10 in which said second plane is perpendicular to said first plane and said second and fourth seal means extend along the same side of said window as the means by which said frames are pivotally connected, separated therefrom by the depth of said sub-frame.
 12. The window of claim 10 in which said second plane is at an acute angle relative to said first plane and said second and fourth seal means extend along the same side of the window as the means by which said frames are pivotally connected and are closely adjacent the pivotal connection thereof.
 13. The window of claim 10 including a plurality of windowpanes mounted in said sub-frame in sealed relationship therewith and spaced from one another to define a sound attenuating airspace therebetween.
 14. The window of claim 13 including means for connecting said airspace to an air drying and filtering breather system regardless of the relative pivotal positions of said main and sub-frames.
 15. The window of claim 10 wherein said first through fourth seals are substantially duplicated near the inner and outer edges of the window to define a sound attenuating airspace between said main and sub-frames when said frames are pivotally aligned and said window is fully closed. 